1. Field of the Invention
This invention relates to the conditioning of small electrical cells of the type that are used in hearing aids, cameras and other electronic instruments.
2. The Description of the Prior Art
Typical summaries of the prior art with which this application is concerned may be seen in U.S. Pat. No. 4,282,474 for LIFE-PROLONGING DEVICE FOR HEARING AID BATTERIES and U.S. Pat. No. 4,352,052 for adaptor for charging small cells in large-cells charger. In these prior art patents and from other sources it may be determined that the small batteries, sometimes referred to as "button" batteries used in hearing aids and other electronic instruments are capable of providing substantially longer service than is normally encountered in situations wherein the battery is continuously used until the instrument no longer works. In other words, a typical battery is constructed of an exterior case having a positive and negative terminal and an interior containing a chemical extending between the terminals. In the course of supplying current to the instrument in which the battery is used, the chemical reaction results in a polarized coating on one or the other or both of the terminals interiorly of the battery and this coating, known as polarization, presents an impediment toward the flow of current and to the chemical reaction necessary to generate the electrical energy so that, even though the chemicals and electrodes are present and are not exhausted, the reaction that is necessary to the generation of electrical energy ceases. In order to, in effect, renew or "recharge" the battery, it is necessary to condition the battery by applying a reverse flow of current through the battery to be restored and, when this is accomplished, the flow of current through the battery results in a depolarization to remove the barrier or impediment to further operation as a source of electrical energy.
In one of the prior art patents referred to above, an adapter is provided for permitting a small battery to be used in a battery charger, or source of current, that will only handle large batteries such as the familiar AA, C or D cells. In the other of the patents referred to above a housing is provided in which an actual battery, such as a C or D battery, is disposed to provide a larger source of energy for conditioning a smaller battery of the hearing aid type. In this patent, small contacts are provided for connecting one battery to another and become, in effect, a battery holder that is difficult to manipulate by the user.
In prior art devices such as those illustrated above, either a requirement for precision manufacturing, large number of parts to be assembled, difficulty in using and other factors to numerous to be noted, have resulted in a lack of general acceptance by the users of small batteries for prolonging the life of the small batteries by utilizing the conditioning process known as "depolarizing" and wide scale adoption of this process has not occurred.
My invention provides a conditioning device for small batteries that is inexpensive to fabricate, has few parts and therefore presents no service problems, and more importantly, is easy to use by individuals lacking manual dexterity for one reason or another. As will be described in greater detail below, my battery rejuvenator consists of a hollow cylindrical casing having a removable cap and a holder for small batteries, of various sizes, that is contained within the housing when the removable top is in a locked position. The flow of the conditioning or depolarizing current from a large battery contained within the housing to a small battery is initiated immediately and automatically as the unit is assembled. The user needs to do nothing except to allow the battery sufficient time to become conditioned or polarized and after the passage of a suitable amount of time, the cover is removed, the battery is removed from the holder and may be reinserted for further service in the instrument in which is utilized. In one sense, the operation of my small battery rejuvenator is automatic in that the large battery contained therein is connected to the small battery to be depolarized in such a manner that a current will continue to flow until the depolarization has been accomplished at which point the voltages of the small and large batteries will be the same and the current will no longer flow so that there is no hazard associated with unattended operation. The user will typically become accustomed to the length of time it may take for a battery to become polarized and may thereafter remove a small battery from an electronic instrument and place the same in my device for depolarization at predetermined time intervals.